I went to the Barrett Jackson auction in Scottsdale, AZ last weekend and got a chance to borrow a buddy's Canon EF 15mm F/2.8 "Fisheye" lens. I got a chance to use it for a few hours on my 5D MkIII and was really impressed with its functionality in this type of situation.

The functionality was greatly enhanced by my DxO Optics Pro 8.1 software that I use for Raw conversion. DxO will de-fisheye if I like, producing a rectilinear image from the original image.

Here's an uncorrected image of a really long boat:Untitled by dcstep, on Flickr

As you see, using de-fisheyeing software, it moves from novelty to serious tool. It allows you to get in front of the crowd and/or obstacles at venues like shows, to get shots that would have had to be multi-shot panoramas with something like a 24mm lens.

I haven't bought it yet, but I plan to buy one. Canon has a couple of 14mm L-series lenses for four times as much as this little lens. I'm not sure that I will pay that difference. When I look at these shots in larger sizes, I'm very pleased with the corner sharpness. I'll do a little more comparison and, perhaps, look for a used 14mm, but I think this is the way that I will go.